Search form

You are here

How fast can LiFi be?

Submitted by hxh on Sat, 28/11/2015 - 13:17

LiFi could transmit up to 100 Gbps and possibly higher, but this would require a change in lighting technology.

Recent news report that LiFi is 100 times faster than WiFi. The assumption was that the average WiFi speeds are 10 Mbps, and that LiFi can be as fast as 1 Gbps. It is important to highlight that 1 Gbps transmission speeds from an off-the-shelf commercial LED light bulb have not been demonstrated, yet. In this discussion, it is important to compare like-for-like. The facts are:

The visible light spectrum is 1,000 times larger than the entire 300 GHz of radio, micro wave and mm wave radio spectrum, so there is a big untapped reservoir of resources for wireless systems.

The current and future growth of wireless data traffic will mean that the radio frequency spectrum will not provide sufficient resources by 2025.

Phosophor coated white LEDs which are mostly used in all commercial lighting devices can deliver up to about 100 Mbps

More expensive red, green, blue (RGB) LEDs can deliver up to about 5 Gbps, and allow control of colour.

The fastest WiFi in the 60 GHz frequency band, WiGig, can achieve a maximum data rate of 7 Gbps

The experienced data rate in a network where multiple users must share the bandwidth is significantly lower than the maximum headline data rate in WiFi systems.

Therefore, a more important metric is the data rate per square meter, or area data rate.

The area data rate of a LiFi network can be 1,000 times higher than the area data rate of a WiFi network. Please download this paper if you want to see the science behind this: ECOC 2015, invited. The main reason for this massive improvement is that, while there can only be one WiFi router in a room as interference would destroy the bandwidth, there can be tens and more light bulbs in a room as interference behaves entirely different when using light to carry data.